PATIENT SELECTION FOR SURFACE REPLACEMENT
Mr M Thomas, Consultant Orthopaedic Surgeon, Heatherwood Hospital, UK
Presented at: International Shoulder Symposium - Leysin, Switzerland - 4-5 March 2005
The indication for surface replacement arthroplasty is identical to that of stemmed implants in elective cases. It is not however suitable for the treatment of acute proximal humeral fractures. Thus the Copeland surface replacement arthroplasty has been used in the following conditions:
- Trauma – post-traumatic arthritis
- Avascular necrosis
- Arthritis of recurrent dislocations
- Rheumatoid arthritis
- Juvenile Idiopathic Arthritis
- Cuff tear arthropathy
The clinical indications are identical to those of stemmed implants but being bone preserving there are definite advantages from using this implant especially in the young patient.
It is contraindicated as with other implants when there is active infection, paralysis of the cuff and deltoid and in the neurotrophic shoulder. It obviously cannot be used in the absence of a humeral head but can be used when 60% of the head only is remaining, the defect being filled with bone graft or possibly bone substitute.
Surface replacement has many advantages over stemmed implants. It is bone preserving and therefore indicated in the young patient where future revision may be anticipated eg avascular necrosis of the humeral head or in Juvenile Idiopathic Arthritis
It also retains the humeral shaft for elbow replacement, negating the vacant segment stress riser effect, and therefore in the patient with rheumatoid arthritis it should be the preferred implant.
It may also be used when there is abnormal proximal humeral anatomy. In post traumatic arthritis tuberosity osteotomy and reconstruction to treat fracture malunion is a difficult procedure and the results are invariably disappointing. Surface replacement allows the arthritis to be treated without requiring proximal humeral reconstruction. Resurfacing is also indicated when there is bowing in the proximal humeral shaft, which can make the insertion of a stemmed implant difficult or impossible.
Finally surface replacement arthroplasty is minimally invasive of bone and therefore may cause less pain which has allowed successful insertion of this implant under interscalene block only in a patient with such severe obstructive airways disease that general anaesthetic or indeed any form of sedation was impossible.